Got a tripod mount problem I need help with.

Greeting fellow travellers!
I recently bought a new Mamiya RB67 body replace the one that I used to have. The mirror reset lever had become jammed and it was going to cost £100 to fix at my local camera shop, so I took a punt on ebay at a £50 replacement body and it's all good. Except...
The tripod socket on the bottom of the body is currently too big for the mount that I have for my current tripod head, a Manfrotto 460MG. I only discovered this the other day when out taking the new body through its paces and I was unable to mount it on my tripod. Luckily the light levels weren't too low, but this could be a future problem. Some pictures to illustrate:
[epzimg]mount--1-of-3-.jpg[/epzimg]
Underside of the new Mamiya body
[epzimg]mount--2-of-3-.jpg[/epzimg]
Underside of old Mamiya body
[epzimg]mount--3-of-3-.jpg[/epzimg]
Current tripod tray mount
As you can see the thread on the new body (pic one) is larger than that on the old body (pic two). Using a ruler and rough numbers, the thread on pic one is about roughly 1cm wide and the thread on pic two roughly 0.6cm.
The screws for the mounts on the two bodies are very tight indeed and whilst this is reassuring whilst out in the field, they are a bugger to try and get off. I've tried and tried to unscrew them but they just won't give. I don't really fancy taking it to a camera shop and getting charged over the odds for a small job, so I think buying a new tray to fit the larger thread size may be a solution, and this is the thrust of my question.
Can I get an attachment similar to the one shown above for screwing in to the bottom of my camera that has a larger thread size that will fit a Manfrotto 460GM head? Are there attachments available that have different thread sizes to accommodate different attachments and, if they are available, where is a good place to look?
Cheers,
Michael.

Greeting fellow travellers!

I recently bought a new Mamiya RB67 body replace the one that I used to have. The mirror reset lever had become jammed and it was going to cost £100 to fix at my local camera shop, so I took a punt on ebay at a £50 replacement body and it's all good. Except...

The tripod socket on the bottom of the body is currently too big for the mount that I have for my current tripod head, a Manfrotto 460MG. I only discovered this the other day when out taking the new body through its paces and I was unable to mount it on my tripod. Luckily the light levels weren't too low, but this could be a future problem. Some pictures to illustrate:

Underside of the new Mamiya body

Underside of old Mamiya body

Current tripod tray mount

As you can see the thread on the new body (pic one) is larger than that on the old body (pic two). Using a ruler and rough numbers, the thread on pic one is about roughly 1cm wide and the thread on pic two roughly 0.6cm.

The screws for the mounts on the two bodies are very tight indeed and whilst this is reassuring whilst out in the field, they are a bugger to try and get off. I've tried and tried to unscrew them but they just won't give. I don't really fancy taking it to a camera shop and getting charged over the odds for a small job, so I think buying a new tray to fit the larger thread size may be a solution, and this is the thrust of my question.

Can I get an attachment similar to the one shown above for screwing in to the bottom of my camera that has a larger thread size that will fit a Manfrotto 460GM head? Are there attachments available that have different thread sizes to accommodate different attachments and, if they are available, where is a good place to look?

There are two sizes of tripod mount, and you can insert a thread reducer into the thread on your new body. Looking at the photos you seem to have one fitted to your original camera which can be removed with a suitable screwdriver. Failing that you could purchase a new one at a minimal cost.

There are two sizes of tripod mount, and you can insert a thread reducer into the thread on your new body. Looking at the photos you seem to have one fitted to your original camera which can be removed with a suitable screwdriver. Failing that you could purchase a new one at a minimal cost.

The old body looks like it has an adapter fitted to reduce the metric thread down to the 1/4 Whitworth, if you can unscrew this then you can put it in the new body. Otherwise look on Ebay for this [link=http://www.ebay.co.uk/itm/1-4-Female-to-3-8-Male-Threaded-screw-Adapter-TN-1-/110701401780?pt=LH_DefaultDomain_3&hash=item19c65156b4]adapter[/link]

The old body looks like it has an adapter fitted to reduce the metric thread down to the 1/4 Whitworth, if you can unscrew this then you can put it in the new body. Otherwise look on Ebay for this adapter